all WAS well in the idleing department

OK guys, I'm stuck,
last night i reassembled the carbs and put them on the bike, its a 81or 82 XJ750J after adjusting the enrichment screws, and the idle knob i had it idling at 1100 perfect, no wet plugs, good color, great response from the throttle, all using a surrogate tank, the ones with the small plastic tank, fuel line and shut off valve at the bottom of the tank,

this morning i put the tank on fired it up and BAMB right up to 3 thousand rpm, thought oh caught the throttle cable got it tight. i was wrong i checked the throttle cable and it was fine, still high, unhooked the throttle, choke. No change. screwed the idle knob way down, no change.

the Carbs are spotless, passes the clunk test before I put them back on, bright shiny slides and passages, clear ports and jets. i didn't touch the float height but cleaned the whole thing in out,

WHAT HAPPENED :cry: :cry: :cry:

i had it after pulling the tank tonight and putting the surrogate on again i still can't get it to idle down.

gonna go get a propane torch to test for air leaks, and maybe pull the covers off the carbs to check the slides, but after that I'm stuck.

Any ideas??
PLEASE??

 

take off one of the carb boots & check that nothing is holding the butterflys open.

 

Is your choke cable too tight?

 

Bad gas? Rust, etc from the tank? Do you have a filter on it?

 

i tried to run it without the throttle or the choke hooked up so its not in the linkages, i will remove a boot and check the butterfly valves, i pulled the plugs and found all to be in good shape except for the 3rd one, pitch black, could i have a stuck needle or slide? would that possibly expian the sympotoms?

 

and yes i have a fuel filter on it

 

Back-off the Idle Adjustment Rod
Check that there is sufficient slack in the Throttle Cable
Run the Bike
Press down on Sync Screws with Pencil eraser to eliminate possible linkage fault
Spray Carb Cleaner directly on critical areas to check for air leaks
Manifolds where they mate to the Head
Manifolds
Touch Manifolds with screwdriver while spraying to help detect cracks
Carb necks into Manifold Ports
Carb Throttle Hinge Points -- Inner and outer

If the revs increase you have an air leak.

 

is your vac line on #3? if so sounds like a bad petcock.

 

Test for the presence of Fuel leaking from the Petcock into the Number-3 Manifold from a possible perforation of the Petcock Vacuum Diaphragm.

(Not necessary if the Petcock is not hooked-up to the 3-Manifold)

 

so the problem was twofold, the slide was stuck, for some reason removed the caps and repolished the works, slide and passages. slight improvement down to 2000rpm. took a break and went back at it with a clear head found my throttle cable was tight agian, even though i disconnected it in a previous trial (so the slide WAS stuck) rerouted the cable and set the idle, and took it for its first spin in 15 years

ALL THANK TO THE GUYS HERE AT XJ BIKES!!!!!!

 

We are at about the point where everybody who has not done any Carb work to insure that their Diaphragm Pistons are free-rising and falling are going to begin having some difficulties, I'm afraid.

Blame "Father Time"

 

Rick, I think you're right. The relatively 'narrow' age range on all our XJ's puts them in the same "generation" if you will, and they're all ageing together with the common problems that result. Kinda like "baby boomers..."

 

thats the funny thing, i torn the carbs apart found several challenges and polished the passages to a shine, i used ma's aluminum compound and a very mind abrasive in the actual slides and thought i had it good but atfer this i was a little harder on the slides, not so much that the brass coate off but apparently enough, also i dissassemled the needles and springs onthe slides and went over them better too, oh well, i got the basic idea and it runs now so thanks guys